/Engine/Source/Editor/UnrealEd/Public/Kismet2/BlueprintEditorUtils.h
Find how many nodes reference the supplied actor
static bool FindReferencesToActorFromLevelScript ( [ULevelScriptBlueprint](API\Runtime\Engine\Engine\ULevelScriptBlueprint) * LevelScriptBlueprint, [AActor](API\Runtime\Engine\GameFramework\AActor) * InActor, [TArray](API\Runtime\Core\Containers\TArray)< [UK2Node](API\Editor\BlueprintGraph\UK2Node) * > & ReferencedToActors )